With revenue from the sales of recordings down in recent years, rock stars are looking for other ways to make money. Sales of CDs are down because of downloading and file sharing. So some of them have gone back to school to take business classes, sold their songs to be used in TV commercials and have formed partnerships with corporations. Some say they should stay pure, caring only about their music and not "go commercial." The New York Times today had an article on this called If It’s Retail, Is It Still Rock?.